Electrolyte cell

ABSTRACT

The invention relates to an electrolyte cell with an end anode and an end cathode and bipolar cell elements disposed between outer cell elements comprising these and electrically connected with them and connected in series one with the other, wherein each cell element comprises one or two gas diffusion electrode(s) of which one forms simultaneously the ceiling of the subjacent electrolyte chamber and the floor of the superjacent electrolyte chamber and the end anode and the anodes of the bipolar cell elements comprise a perforated, electrically well-conducting electrode structure, wherein each electrolyte chamber is charged with electrolyte and reaction gas, such as oxygen, and a particular mixture of electrolyte and the resulting product as well as residual reaction gas are drawn off from each electrolyte chamber, wherein the cell elements are combined in the form of a stack, that [sic] the end cathode and the cathodes of the bipolar cell elements comprise a perforated, electrically well-conducting support wall on which rests in each instance one gas diffusion electrode, and that [sic] the overflows provided at the particular upper cell elements are adjustable with respect to height.

BACKGROUND OF THE INVENTION

The invention relates to an electrolyte cell with an end anode and anend cathode and cell elements disposed between outer cell elementscomprising these and electrically connected to them and connected inseries with one another, wherein each cell element comprises one or twogas diffusion electrode(s), of which one forms simultaneously theceiling of the subjacent electrolyte chamber and the floor of thesuperjacent electrolyte chamber as well as the end cathode and theanodes of the bipolar cell elements comprise a perforated, electricallywell-conducting electrode structure, for example of nickel, wherein eachelectrolyte chamber is charged with electrolyte and reaction gas, suchas oxygen, for example in the form of air, and a particular mixture ofelectrolyte and the resulting product as well as residual reaction gasis drawn off from each electrolyte chamber. Such an electrolyte cell hasfor example been suggested for the generation of ammonium polysulfide(APS) to which as the electrolyte is supplied an aqueous ammoniumsulfide solution and from which is drawn off a solution comprisingammonium polysulfide. The electrolyte cell comprises an anode, a gasdiffusion cathode and an electrolyte chamber disposed between the anodeand the cathode. The cathode comprises an electrically conducting,gas-permeable carbon layer against which flows the gas comprising freeoxygen and which is in contact with the electrolyte. Gas containing freeoxygen is conducted into the electrolyte chamber and hyperoxide anions(OOHO--) are formed in it. From the electrolyte chamber are drawn off asolution containing ammonium polysulfide and a residual gas. Associatedwith the cathode is an areal, permeable metal element, for example ametal mesh or expanded metal, to which is connected a carbon layer. Thecarbon layer can be a carbon cloth coated with a mixture of graphite andPTF particles.

The use of a carbon cloth in gas diffusion electrodes is problematic inall application cases for the following reasons: into the gas diffusionelectrode gas must diffuse, i.e. it must be porous. On the other hand,it is necessary to prevent gas from penetrating through the gasdiffusion electrode since the desired reactions take place only on thesurface of the electrolyte within the gas diffusion electrode. Thismeans that fluid must also diffuse into the electrode. In the case offuel cells this problem has been attempted to be solved thereby that theelectrolyte was immobilized, i.e. a cloth or a felt was impregnated withthe electrolyte. Thus, in each instance two porous cloths, namely forexample the felt impregnated with the electrolyte and the gas diffusionelectrode, are opposing one another in pressing contact with eachmoistening the other one, but not permitting penetration of the fluid.

In electrolyte processes in which substances dissolved in theelectrolyte are to be converted and in which the solubility of thesubstances is limited, immobilizing the electrolyte is not possible. Inthe electrolytic generation of H₂ O₂ in an alkaline electrolyte, forexample, the throughput of sodium hydroxide is determined by thesolubility of Na₂ O₂ in the sodium hydroxide. If the carbon cloth on theside facing the fluid is made hydrophilic, and, on the side facing thegas, is made hydrophobic by impregnating the side facing the gas withPTFE, the electrolyte can penetrate up to the hydrophobic layer in thegas diffusion electrode. The gas can penetrate into the hydrophobicportion up to the hydrophilic portion filled with electrolyte. Thereaction takes place at the boundary layer in the pores of the, overall,porous cloth. Due to differing capillary forces of the two differentlayers, however, the separating force is not unlimited. It is in generalapproximately 0.025 bar. However this also means that at a density ofthe electrolyte of 1 g/cm³ the height of one electrode is limited to 25cm. This means further that the pressure difference in the reactionvolumes can also not be greater than 0.025 bar. If it were greater, thegas would bubble through the upper portion of the perpendicular cloth.If it were less or if the electrolyte pressure were higher, theelectrolyte would penetrate through the lower portion. In both cases thegas diffusion electrode would be inactive in these areas. In addition,capillary forces are a function of the adhesion of the fluid. Thus theelectrolyte would demand a different level at each temperature. This,however, impairs the large-scale industrial application of thistechnology, in particular in extractive metallurgy. In the extraction ofmetals, the electrodes are, as a rule, taller than one meter. Floodingthe gas diffusion electrode could for example only be avoided therebythat the metal extraction electrolysis is operated in vacuo such thatelectrolytes penetrating through the gas diffusion electrode are drawnoff at the bottom from the electrolyte cell, for which additionalexpenditures are required.

Another possible solution of this problem comprises placing theelectrodes horizontally. However, this cannot be realized inelectrolyses for extracting metals since in this case open electrolyzerare used, from which metal in the form of solid cathode deposits must beremoved at regular intervals.

Such an approach would, incidentally, fail for economic reasons.Horizontal cells are monopolar cells. Therefore, a multiplicity of cellswould need to be electrically connected in series, such as, for example,in the case of the so-called mercury cell for generating chlorine andsodium hydroxide. In the present case this fails due to the currentdensity which is far too low in gas diffusion electrodes. Due to theirporosity the exchange of material is limited. As the limit of currentdensity are generally considered 2 kA/m². In mercury electrolyses forchlorine generation, in contrast, it is possible to work with currentdensities up to 15 kA/m². At an equivalent production, the required areawould thus increase by a multiple. For this reason, monopolar cells forlarge-scale industrial processes are in general equipped with verticalelectrodes.

It is the task of the present invention to eliminate in an electrolytecell of the above cited type the described disadvantages and to ensurereliable and continuous application at high efficiency.

This task is solved according to the invention for example thereby thatthe cell elements are combined in the form of a stack, that the endcathode and the cathodes of the bipolar cell elements comprise aperforated, electrically well-conducting support wall, for example ofnickel, on which is disposed in each instance one gas diffusionelectrode, and that the overflows provided at the cell elements areadjustable with respect to their height.

In this way it is possible to ensure that at no site of the electrolytecell a hydrostatic pressure occurs which is higher than the penetrationresistance of the gas diffusion electrode, implemented for example as acarbon cloth. The difference of the hydrostatic pressure from thepenetration resistance of the gas diffusion electrolysis [electrode] canbe such that, for example, the reaction gas flows sequentially throughthe cell elements at decreasing pressure. Such an interconnectioncontributes to the greater utilization of the gas. The stack of bipolarcells have a minimum space requirement; the number of superjacent cellelements is virtually unlimited. The required pipe lines are short. Dueto the bipolar arrangement it is not necessary to use bus bars betweenthe cell elements although the cell elements are electrically connectedin series. Due to this interconnection the necessary electric energy isrequired at low current strength and high voltage which makes thetransformers and rectifiers used cost-effective.

Due to the gas diffusion electrode, the invented electrolyte cell isprimarily intended for the chemical conversion of oxygen at the surfaceof the aqueous electrolyte, to which is applied a voltage from theoutside. The selectivity and the strength of the oxidation energy at thegas diffusion electrode can be set by means of the selection of suitableelectrolytes but also by means of different catalysts, for examplethrough platinum.

As such, the electrolyte cell can serve for example also as a fuel cellfor generating energy if to both polarities gases reacting with eachother are supplied from the outside. In contrast to conventional fuelcells, the value created is comprised in the reaction product generated.If oxygen generated at the anode is converted with hydrogen suppliedfrom the outside, the electrolyte cell constructed in this way servesfor decreasing the voltage and thus to save high-cost electric energy.

This is of interest especially if anodes with high oxygen overpressurecan be replaced by gas diffusion electrodes. This applies, for example,to the electrolytic generation of metals with special emphasis on Zn andCu. The invented electrolyte cell is preferably applied for theelectrolytic generation of H₂ O₂ by oxidation of the H₂ generated at thecathode with relatively complicated processes occurring in alkalinesolution with O₂ With a catalyst-free gas diffusion electrode the energysaving is approximately 0.6 V, the heat of formation of Na₂ O₂, whichforms in alkaline solution, correspondingly approximately 450 kWh/t H₂O₂.

A further technical application comprises the so-called Hydrina processin which Na₂ SO₄, which accumulates in large quantities as aneutralization product of H₂ SO₄ and NaOH, is again split into itsstarting products in the electrolysis. When using a gas diffusionelectrode catalyzed with platinum as anode or as cathode and flow of H₂,respectively O₂, each over the electrode of opposite polarity, thefollowing reaction equation results:

    Na.sub.2 SO.sub.4 +3H.sub.2 O=H.sub.2 SO.sub.4 +2NaOH+H.sub.2 O-69.3kcal,

i.e. the energy requirement is limited to the heat of neutralization ofacid and base.

With the electrolyte cell according to the invention the principle ofthe redox processes can basically be applied to any reduction/oxidationwherein the desired potentials can be set by means of differentcatalysts in the gas diffusion electrode, whereby the particular desiredreaction proceeds as preferred.

Especially useful embodiments of the electrolyte cell according to theinvention are in the dependent claims.

Whenever the oxidized product at the cathode can be reduced again, it isrecommended to separate the anodes from the opposing cathodes by meansof a diaphragm.

The diaphragm can therein be a cloth or a fiber mixture drawn onto theanode by suction, but it can also be an ion exchange membrane.

For specific application cases, for example in the production of H₂ O₂,the gas diffusion electrode can be free of catalyst.

For operation as a fuel cell, the anodes and the cathodes areadvantageously covered with a gas diffusion electrode which isimpregnated with the catalyst, and the cell elements are each divided bya gas-tight horizontal separating wall.

The particular cathode of the bipolar cell elements, in particular itselectrode structure, can be connected via electrically conducting websprovided with penetration openings for gas, respectively gas and fluid,comprising for example nickel. When dividing the cell elements by aseparating wall, a corresponding penetration opening is provided in thewebs on each side of the separating wall.

To ensure economic construction of the electrolyte cell, the housings ofthe cell elements can be connected by means of edge flanges byinterplacing electrically insulating seals such that they are gas- andfluid-tight.

Preferred functional operation results if the cell elements areconnected in parallel with respect to the electrolytes. This operatingmanner is especially of advantage if low current strengths must besupplied in large quantities of electrolyte. This is for example thecase when sterilizing water.

In the case of cell elements connected electrically and, with respect tothe electrolytes, in series, preferably a particular mixture ofelectrolyte and the resulting product as well as reaction gas can betransferred from the electrolyte chamber of an upper cell element viaconnection lines to the electrolyte chamber of a lower cell element, andfrom the lowest cell element can be drawn off electrolyte and productand potentially residual reaction gas.

The connection lines associated with the overflows usefully terminatelaterally in the particular lower cell element such that simple assemblyis possible.

Further goals, characteristics, advantages and application feasibilitiesof the invention are evident in the following description of embodimentexamples in conjunction with the drawing. All described and/orgraphically depicted characteristics form by themselves or in anycombination the subject matter of the invention even independently oftheir summary in the claims or their reference back.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 depicts schematically the structure of an electrolyte cellaccording to the invention by example of the generation of H₂ O₂,

FIG. 2 depicts schematically the detail of a bipolar cell element for acell element stack for an electrolysis operation, and specifically FIG.2a such a one without redox processes, and FIG. 2b one with redoxprocesses, with a separating layer being provided on the anode,

FIG. 3 depicts a schematic representation similar to that of FIG. 1,however modified for the operation of the electrolyte cell as a fuelcell, and

FIG. 4 depicts a representation similar to that of FIG. 2, however withthe cell element being implemented for operating the electrolyte cell asa fuel cell.

FIG. 1 represents an electrolyte cell as a stack of bipolar cellelements E1 to E5 stacked one above the other. The different polaritiesare denoted by (+) for the anodes A1 to A4 and by (-) for the cathodesK2 to K5. The two end electrodes A1 (end anode) and K5 (end cathode)have naturally only one polarity. In the topmost cell element E1, airand sodium hydroxide (NaOH) are supplied via a supply line 1. Due to thesingle polarity in the cell element E1, only oxygen is formed. The anodeA1 comprises an expanded (mesh) metal, a textile or perforated sheetmetal comprising nickel or any other metal or material which has goodelectrical conductivity and is corrosion resistant under the givenconditions. The anode A1 can be separated from the opposing cathode K2by a diaphragm or a membrane 13 (cf. FIG. 2b and 3). This is recommendedwhenever the oxidized product can be reduced again at the cathode K2 toK5. The diaphragm 13 can be a cloth or a fiber mixture suctioned ontothe anode A1 to A4 and burned in, or a porous thin plate comprisingsynthetic material basically only allowing the current to pass; themembrane must have ion exchange properties.

If, as described, via the supply line 1, air or air and oxygen areintroduced into the cell element 1, these are mixed with the oxygenformed there and the resulting gas mixture is output via the connectionline 2 to the cell element E2. In the cell element E2 two polaritiesobtain, namely the cathode K2 and the anode A2. The cathode K2 servesaccording to the invention simultaneously as the floor of the first cellelement E1. Like the anodes A1 and A2, the cathode K2 comprises, forexample, a nickel structure, on which rests the carbon cloth, which inthis example is not impregnated with catalyst, to form a gas diffusionelectrode 11. At the cathode K2 the H₂, which normally develops here, isconverted by the O₂ present in the gas diffusion electrode 11 to H₂ O₂which is dissolved as Na₂ O₂ in the NaOH used as electrolyte and movestogether with it through the connection line 2 into the cell element E2.

Analogously, through the connection lines 3 and 4, the NaOH becomingenriched with Na₂ O₂ on its path downwardly, together with the air beingslowly depleted of O₂, enters the cell elements E3 and E4, which isexited via the output line 5.

In cell element E5, Na₂ O₂ is formed for the last time so that theelectrolyte, comprising NaOH containing Na₂ O₂, can here be separated.But it can also be introduced together with the mixture of O₂ and N₂through a feedback line 6 into the cell element E5. O₂ serves in thecell element E5 for the purpose of ensuring that Na₂ O₂ can still beformed in cell element E5.

N₂ and residual O₂ leave the system through the output line 7.

The level of the electrolyte lastly borne by the carbon cloth can beadjusted in any desired way by means of the disposition of the overflows12 of the connection lines 2 to 4, respectively the output line 5.Likewise, by means of the lateral supply of the electrolyte the intervalof the two electrodes A1 to A4 and K2 to K5 is not affected. Therewith,in order to keep the voltage drop, and thus the energy consumption, to aminimum, the mechanically and flow-technologically least possibledistance of the two electrodes from one another can be set. This ensuresthat a hydrostatic pressure higher than the penetration resistance ofthe carbon cloths cannot occur at any site of the system.

The stack of bipolar cell elements E1 to E5 has a minimum spacerequirement since the number of superjacent cell elements E1 to E5 isvirtually unlimited. The pipe lines are short. Due to the bipolararrangement bus bars are not required between the cell elements E1 to E5although the cell elements E1 to E5 are electrically connected inseries. Due to this interconnection the necessary electric energy isrequired at low current and high voltage which makes transformers andrectifiers cost-effective.

In FIG. 3 is illustrated the operation of the electrolyte cell as a fuelcell. In this case the diaphragm 13 or the membrane of the anodes isreplaced by a Pt-impregnated carbon cloth (FIG. 4); the carbon cloth atcathode K2 to K5 is also impregnated with Pt.

The electrolyte, in the present case NaOH, is supplied to the system viathe supply line 31 and runs through the stack of cell elements E1 to E5through the connection lines 32 to 35 and the output line 37. Theoverflows 12 of the electrolyte are set such that the anodes A1 to A4with the gas diffusion electrode implemented as carbon cloth are onlyimmersed; however, the carbon cloth is not penetrated.

To the anodes A1 to A4, H₂ is supplied from the outside through (notshown) pipe lines. In the electrolyte cell no longer is any oxygenformed but [rather] water. To the cathodes O₂ in the form of air or assuch is also supplied to the system from the outside. In order to avoidinternal mixing of the two gases O₂ and H₂, the bipolar cell elements E2and E4 are divided gas-tight into two separate volumes by separatingwalls T2 to T4.

FIG. 2 illustrates the detail of a bipolar cell element E for anelectrode stack according to FIG. 1 if operated as electrolysis withoutredox processes, i.e. without a separating layer on the anode A, in anenlarged detail. The electrode structure 9 of the anode A and thesupport wall 10 of cathode K are connected one with the other viaconducting webs S, which, for example, in the case of H₂ O₂ generation,comprise nickel. On cathode K rests a gas diffusion electrode (GDE) 11comprising carbon cloth and is thus also connected with it so as to beconducting. Each web S is provided with at least one gas penetrationopening G.

FIG. 4 shows in a detail corresponding to FIG. 2 a bipolar cell elementE for an electrode stack operating as a fuel cell. Both electrodes arecovered with a gas diffusion electrode 14, respectively 11. Due to theseparating wall T the connection [sic] webs S are provided on each sidewith a penetration opening G for gas.

The bipolar cell elements, in particular in this interconnection as fuelcell for generating electric energy, show significant advantagesrelative to prior art. In the known cells the electrolyte isimmobilized. Without appropriate countermeasures the resulting waterwould dilute the electrolyte, flood the electrolyte volume and woulddisable its function. For this reason, the cells are operated at atemperature at which water evaporates from the electrolyte. But aqueouselectrolytes most frequently comprise highly soluble, hygroscopicsubstances such as alkali liquors or phosphoric acids to conduct thecurrent. During the evaporation of water, these show a correspondingincrease of their boiling point, which lowers the partial pressure ofthe water above the electrolyte to below that of pure water. Theoperating temperature would have to be increased which, given theaggressive properties of the electrolytes, would entail materialproblems.

In order to avoid this, the partial pressure of the water in the fuelcell is decreased. This is accomplished thereby that the reaction gasesO₂ and H₂ are not 100% utilized. The evaporation is converted into avaporization. The heat of vaporization is a portion of the electricenergy generated in the fuel cell, which is converted into heat throughthe internal resistance of the cell. A substantial portion of theinternal resistance is caused by the resistance of the electrolyte,which, in turn, is substantially increased by means of the material forthe immobilization of the same.

The conditions with the electrolyte cell according to the invention canbe formed significantly more favorably. The quantity of the pumped-overelectrolytes can be adjusted such that the generated water as well asalso the generated heat can be taken up. Utilization, in particular ofthe hydrogen, can be increased. The internally generated quantity ofheat to be considered as loss and the quantity of the generated waterare uncoupled. This increases the flexibility of the operation of thecell since the quantity of water generated increases linearly with thepower, however the internally generated quantity of heat [increases] asthe square. The operating temperature of the electrolyte cell can beoptimized according to its requirements. The necessary water evaporationcan be moved to the outside into an evaporator laid out for this purposeand can potentially be carried out in multiple stages. The efficiency ofthe fuel cell is overall increased.

List of Reference Symbols

1 Supply line

2 Connection line

3 Connection line

4 Connection line

5 Output line

6 Feedback line

7 Output line

8 Electrolyte chambers

9 Electrode structure

10 Support wall

11 Gas diffusion electrode

12 Overflows

13 Diaphragms

14 Gas diffusion electrode

15 Housing

16 Edge flange

17 Seal

31 Supply line

32 Connection line

33 Connection line

34 Connection line

35 Connection line

37 Output line

A1 to A4 Anodes

E1 to E5 Cell elements

GK2 Gas penetration opening

to K5 Cathodes

S Conducing Webs

T2 to T4 Separating walls

I claim:
 1. An electrolyte cell comprising:a plurality of cell elements (E1 to E5) comprising a first external cell element (E1), a second external cell element (E5) and at least one bipolar cell element (E2 to E4); said first external cell element (E1), said at least on bipolar cell element (E2 to E4), and said second external element (E5) being electrically connected in series and aligned in a stack, said first external cell element (E1) and said second external cell element (E5) being on opposit ends of said stack; gas diffusion electrode (11) within each of said first external cell element (E1) and said second external cell element (E5), said gas diffusion electrode (11) in said first external cell element (E1) being an end anode (A1) comprising a perforated, conductive electrode structure (9) and said gas diffusion electrode (11) in said second external cell element (E5) being an end cathode (K5) comprising a perforated, conductive support wall (10).; a plurality of gas diffusion electrodes (11) within each of said at least one bipolar cell element (E2 to E4), one of said plurality of gas diffusion electrodes (11) being an anode (A2 to A4) comprising a perforated, conductive electrode structure (9) and another of said plurality of gas diffusion electrodes (11) being a cathode (K2 to K4) comprising a perforated, conductive support wall (10); a plurality of electrolyte chambers (8) formed between said gas diffusion electrode (11) of said first external cell element (E1), said plurality of gas diffusion electrodes (11) of said at leas one bipolar cell element (E2 to E4), and said gas diffusion electrode 911) of said second external cell element (E5), said plurality of electrolyte chambers (8) being charged with an electrolyte and a reaction gas, wherein a particular mixture of said electrolyte, resulting products and residual reaction gas is syphoned from said plurality of electrolyte chambers (8); and each of said at least on bipolar cell element (E2 to E4) and a top external cell element located on the top of said stack having an overflow (12) having an adjustable height, wherein said top external cell element being one of said first external cell element (E1) and said second external cell element (E5).
 2. The electrolyte cell as claimed in claim 1, wherein said end anode (A1) and said anode (A2 to A4) are each separated from said cathode (K2 to K4) and said end cathode (K5), respectively, by a diaphragm (13) which comprises a gas-tight ion exchange membrane.
 3. The electrolyte cell as claimed in claim 2, wherein each said diaphragm (13) is a mixture comprising one of cloth and fiber suctioned onto said anode (A2 to A4) and said end anode (A1) or a porous thin plate comprising synthetic material which allows only current to pass.
 4. The electrolyte cell as claimed in claim 3, wherein said anode (A2 to A4), said end anode (A1), said cathode (K2 to K4) and said end cathode (K5) are impregnated with a catalyst, and said at least one bipolar cell element (E2 to E4) is divided by a gas-tight separating wall (T2 to T4).
 5. The electrolyte cell as claimed in claim 1, wherein said gas diffusion electrode (11) and said plurality of gas diffusion electrodes (11) are free of a catalyst.
 6. The electrolyte cell as claimed in claim 5, wherein said cathode (K2 to K4) and said anode (A2 to A4) of said at least one bipolar cell element (E2 to E4) are connected via electricall conducting webs (S) which have penetration opening (G) for at least one of gas and fluid.
 7. The electrolyte cell as claimed in claim 6, wherein said at least one bipolar cell element (E2 to E4) is divided by a gas-tight separating wall (T2 to T4), and said penetration openings (G) are provided in said electrically conducting webs (S) on each side of said gas-tight separating wall (T2 to T4).
 8. The electrolyte cell as claimed in claim 6, wherein said electrically conducting webs (S) comprise nickel.
 9. The electrolyte cell as claimed in claim 1, wherein said anode (A2 to A4), said end anode (A1), said cathode (K2 to K4) and said end cathode (K5) are impregnated with a catalyst, and said at least one bipolar cell element (E2 to E4) is divided by a gas-tight separating wall (T2 to T4).
 10. The electrolyte cell as claimed in claim 1, wherein said plurality of cell elements (E1 to E5) are contained in housings (15), said housing (15) are connected by edge flanges (16) and seal rings (17) are between said housings (15) such that said housings (15) are gas and fluid tight and also are electrically isolated.
 11. The electrolyte cell as claimed in claim 1, wherein said cell elements (E1 to E5) are connected in parallel with respect to said electrolyte.
 12. The electrolyte cell as claimed in claim 1, further comprising connection lines (2 to 6) to connect said cell elements (E1 to E5) to enable said particular mixture of said electrolyte, said resulting products and said residual reaction gas of an electrolyte chamber (8) of said plurality of electrolyte chambers (8) to be transferred to another electrolyte chamber (8) which is formed between a plurality of said at least one bipolar cell element (E2 to E4) or said at least one bipolar cell element (E2 to E4) and a bottom external cell element located on the bottom of said stack, said bottom external cell element being one of said first external cell element (E1) and sai second external cell element (E5), and to enable said particular mixture of said electrolyte, said resulting products and said residual reaction gas to be drawn off.
 13. The electrolyte cell as claimed in claim 12, wherein said connection lines (2 to 6) terminate at a next lower cell element (E2 to E5) from which said connection lines (2 to 6) originated and each of said connection lines (2 to 6) is associated with said overflow (12) of said cell element from which it originated.
 14. The electrolyte cell as claimed in claim 2, wherein said anode (A2 to A4), said end anode (A1), said cathode (K2 to K4) and said end cathode (K5) are impregnated with a catalyst, and said at least one bipolar cell element (E2 to E4) is divided by a gas-tight separating wall (T2 to T4).
 15. The electrolyte cell as claimed in claim 1, wherein said perforated, conductive electrode structure (9) comprises nickel.
 16. The electrolyte cell as claimed in claim 1, wherein said reaction gas comprises oxygen in the form of air.
 17. The electrolyte cell as claimed in claim 1, wherein said perforated, conductive support wall (10) comprises nickel. 